Resistance of high-strength concrete to projectile impact
M. H. Zhang and G. Yang
Department of Civil Engineering, National University of Singapore, Singapore
ABSTRACT: This paper summarizes results from a laboratory experimental study on the resistance of
concrete to simulated impact loading of fragments. The impact of fragments was simulated by the
impact of ogive-nosed projectiles with a diameter of 12.6mm and a mass of 15 grams traveling at
velocities from ~600 to 700 m/s. Effects of fibers, aggregate, curing temperature, compressive and
flexural tensile strength of concrete on the impact resistance are evaluated and discussed. The results
indicate that the incorporation of a small amount of fibers can reduce the crater diameter effectively as
the fibers are able to bridge cracks and to hold concrete together. However, in order to reduce the
penetration depth, reduced water-to-cement ratio and increased strength of the concrete matrix are
required. Nevertheless, when the strength was beyond a certain level, further increase in the
compressive strength did not reduce the penetration depth. Strong aggregate with bigger sizes seems to
be beneficial to improve the impact resistance so long as the workability is satisfactory and the
aggregate sizes meet requirements based on the size of structural members and the spacing between
reinforcing bars and spacing between reinforcing bar and form.